title: A study of physician collaborations through social network and exponential random graph.
abstract: BACKGROUND
  Physician collaboration, which evolves among physicians during the course of providing healthcare services to hospitalised patients, has been seen crucial to effective patient outcomes in healthcare organisations and hospitals. This study aims to explore physician collaborations using measures of social network analysis (SNA) and exponential random graph (ERG) model.
  
  
  METHODS
  Based on the underlying assumption that collaborations evolve among physicians when they visit a common hospitalised patient, this study first proposes an approach to map collaboration network among physicians from the details of their visits to patients. This paper terms this network as physician collaboration network (PCN). Second, SNA measures of degree centralisation, betweenness centralisation and density are used to examine the impact of SNA measures on hospitalisation cost and readmission rate. As a control variable, the impact of patient age on the relation between network measures (i.e. degree centralisation, betweenness centralisation and density) and hospital outcome variables (i.e. hospitalisation cost and readmission rate) are also explored. Finally, ERG models are developed to identify micro-level structural properties of (i) high-cost versus low-cost PCN; and (ii) high-readmission rate versus low-readmission rate PCN. An electronic health insurance claim dataset of a very large Australian health insurance organisation is utilised to construct and explore PCN in this study.
  
  
  RESULTS
  It is revealed that the density of PCN is positively correlated with hospitalisation cost and readmission rate. In contrast, betweenness centralisation is found negatively correlated with hospitalisation cost and readmission rate. Degree centralisation shows a negative correlation with readmission rate, but does not show any correlation with hospitalisation cost. Patient age does not have any impact for the relation of SNA measures with hospitalisation cost and hospital readmission rate. The 2-star parameter of ERG model has significant impact on hospitalisation cost. Furthermore, it is found that alternative-k-star and alternative-k-two-path parameters of ERG model have impact on readmission rate.
  
  
  CONCLUSIONS
  Collaboration structures among physicians affect hospitalisation cost and hospital readmission rate. The implications of the findings of this study in terms of their potentiality in developing guidelines to improve the performance of collaborative environments among healthcare professionals within healthcare organisations are discussed in this paper.
authors.affiliation: Complex System Research Centre, The University of Sydney, Sydney NSW 2006, Australia. shahadat.uddin@sydney.edu.au
authors.forename: Shahadat
authors.initials: S
authors.lastname: Uddin
authors.forename: Liaquat
authors.initials: L
authors.lastname: Hossain
authors.forename: Jafar
authors.initials: J
authors.lastname: Hamra
authors.forename: Ashraful
authors.initials: A
authors.lastname: Alam
mesh_terms: D000465:Algorithms; D001315:Australia; D003299:Cooperative Behavior; D003362:Cost-Benefit Analysis; D006760:Hospitalization / Q000191:economics / Q000639:trends; D006801:Humans; D007345:Insurance Claim Review; D016014:Linear Models; D010359:Patient Readmission / Q000191:economics / Q000639:trends; D058007:Physicians, Primary Care / Q000458:organization & administration*; D012944:Social Support